1. Field of the Invention
The present invention relates to a V-type internal combustion engine with a variable valve train that varies the phase/lift amount of a camshaft.
2. Description of Background Art
Some V-type internal combustion engines in which cylinder blocks are arranged in a V-shape have a variable valve train that varies the phase/lift amount of a camshaft. This variable valve train includes a drive cam that rotates together with the camshaft, a valve cam that rotates relative to the camshaft for opening/closing an engine valve, a link mechanism that transmits the valve driving force of the drive cam to the valve cam, a holder member that supports a fulcrum of the link mechanism and is capable of swinging around the camshaft, and a drive mechanism that swings the holder member to vary the fulcrum position of the link mechanism, and varies the phase/lift amount of the camshaft in accordance with a swing position of the fulcrum of the link mechanism. The variable valve train is driven by an actuator that is mounted above a head cover. See, for example, JP-A No. 2004-190609.
However, the use of the above-described previous configuration, in which the actuator for the variable valve train is mounted above the head cover, increases the height of the internal combustion engine, thereby making it difficult to mount the internal combustion engine in a motorcycle or other small-sized vehicle.